A STUDY OF MECHANISM ON ELECTROMAGNETIC EMISSION ASSOCIATED WITH ROCK FRACTURE
ZHU YUAN-QING Luo XIANG-LIN' Guo ZI-QIANG ZHAO ZHI-GUANG ZHU ZHONG-WEI Shanghai Seismological Bureau, Shanghai 200062Beijing Research Center of Aviation Engineering Technique, Beijing 100076Dept. of Earth arid Space Science, University of Science and Technology of China, Hefei '230026s
A new idea that the distribution movement of electric charge in the crack tip end being associated with rock fracture propagation produces electromagnetic emission was brought up.The relation between initial length of crack and velocity and/or acceleration of crack propagation has been derived and calculated. According to the mechanism of electron emission of rock fracture, the phenomenonthat there is electric charge in the crack tip end can be explained. Some experiment results havebeen applied to estimate the quantity of electron charge in the crack tip end and the strengthof electromagnetic radiation. The top-frequency of electromagnetic radiation of rock fracturehas been estimated by means of spectrum theory and by experiment results.Finally, the phenomena of electromagnetic emission, electron emission, light emission andacoustic emission during rock fracture have been explained uniformly and theoretically.